1. Field of the Invention
The present invention relates to a method of preparing a magnesium oxide structure for use as, for example, a catalyst support or an adsorbent of carbon dioxide. In particular, the present invention relates to a method of preparing a magnesium oxide structure with meso-macro pores.
2. Description of the Related Art
Magnesium oxides are an insulator having a wide band gap and are widely used as a catalyst, a carbon dioxide adsorbent, a refractory material, paint, a superconductor product, or the like. Typically, a magnesium oxide having a controlled nanostructure is obtained by thermal decomposition of various magnesium compounds, such as hydroxide, oxalate, carbonate, or nitrate of magnesium.
Conventionally, activities of solid materials are determined according to their initial chemical processes, and studies on magnesium oxides that are obtained through decomposition paths of various compounds such as magnesium hydroxide or magnesium carbonate report that these materials have high activity for adsorption and catalysis. However, a bottom-up process, which is kind of a method of obtaining a nano-structured magnesium oxide for heterogeneous catalysis, makes a controllable and reproducible use of nanostructures difficult, and thus, an improvement thereof is required.
Meanwhile, a catalyst support used for Fischer-Tropsch synthesis and steam reforming may be prepared to have a meso-macro multiple distributed pores structure in order to have high permeability of a reactive gas and high activity of a catalyst. In addition, a catalyst support needs to have high strength for long-term use under high-temperature and high-pressure reaction conditions, and also needs to maintain a porous nanostructure. That is, when a catalyst support is formed of an inorganic material, calcining at high temperature is required to make the catalyst support have high strength. However, the high-temperature calcining may result in collapse of a porous nanostructure that is constructed to enhance catalysis and difficulty in forming macropores.
Accordingly, there is a need to develop a method of preparing a magnesium oxide structure that enables the formation and maintenance of a nanostructure with a meso-macro pores even at high calcination temperature.